Because of the seriousness of the hazards associated with the use of organophosphorus insecticides, and the primary need to anticipate and assess both short- and long-term accumulative threats to a healthy environment before they reach a critical stage, a comprehensive multidisciplinary research project embracing the exceptional research resources of the University of California, Davis, is currently underway. In our studies, we are hopeful in determining the true factors relating to the environmental fate of parathion and other organophosphorus insecticides, especially as they relate to human health. Broadly, this long-term project includes these areas of study: uptake, penetration, and residues in field crops; movement in air (drift), water and soil (persistence and degradation); and occupational hazards (aerial and ground applications, exposure and decontamination) of agricultural and other workers.